Grinding machine



Jam 30, 1934- c. H. GERLING y 1,945,396 GRINDING MACHINE f y Filed April 19, 1929 Inventor:

Carl HGQPHVK,

KVM/V704@ His ttorney..

Patented Jan. 30, 1934 GRINDING New York Application April 19, 19

arl H. Gerling, Schenectady,

General Electric Company, a

MACHINE N. Y., assigner to corporation of v,

29.v Serial No. 358,537

2 Claims.` (Cl. 51--166) The present invention relates to improved apparatus or machines for grinding or surfacing hard metals and particularly metal compositions which 'consistlargely of a hard metal carbide,

such as tungsten-carbide, but contain an appref a binder or cementing metal such as cobalt. is describe 615. Such compositions preaching that of the diamond and at the present time are employed to a large extent as metal cutting tools, the composition employed being usually in the form of a tool bit which may be welded or brazed to a steel shank Heretofore great diiliculty has been encountered in grinding such tool bits. For example, when ordinary automatic surface grinding maloyed the ground surfaces of the ed or welded tool bit are so to a shank the therefore frequently cra the tool. It is also difficult to obtain a sharp, even edge on the tool when the gr are uneven. Moreover, the tool edge is readily chipped off when the ordinary rigid grinder is employed. These diiliculties have necessitated the use, to a large extent, of hand grinders in surfacing such tool bits. When hand grinders are employed however, the grinding process is not only very slow but expert workmen are required,

since a tool bit may easily be destroyed in the grinding operation. Moreover, it is practically impossible to form accurate angles between ad jacent surfaces of a tool bit with a hand grinding machine.

It is one of the objects of the present invention to provide an improved grinding machine which may be operated by unskilled labor and which is capableof grinding at relatively high speed a perfectly dat surface on hard metals and particularly on cemented tungsten-carbide tool bits.

In carrying out my invention, I provide means whereby, in the usual automatic grinding machine, the grinding wheel may be held in its operative position by resilient means but is capable of a slight limited movement, for example about away from machine of this unskilled labor in grinding the tool bits and produces ground surfaces which are exactly ilat and which may be ground at any exact angle with respect to one another.

The novel acteristic of 55 ticularty in features which I believe to be charmy invention are set forth with parthe appended claims. The invenprovided with a reciprocating table tion itself however will best be understood from reference to the following specincation when considered in connection` with the accom drawing in which Fig. 1 represents a viewpartly in elevation and partly in section of an automatic 'Q surface grinding machine which embodies the features of the present invention, while Fig. 2 is a view partly in sectionl and partly in elevation of a cutter grinder which also embodies features of the present invention.

Referring more particularly to the drawing, I have indicated at 1in Fig. 1 the framework of an ordinary automatic surface ygrin e. 2 adapted to`v be driven in opposite directions by an electric motor 3 connected to reversing gearing 4 through a counter-shaft 5 provided with pulleys 6 and '1. Motor 3 also drives a small pulley 8 which'isattached to the surface grinding wheel 9 through pulleys 6 and 10. Grinding wheel 9 and the attached pulley 8 are providedwith bearings in a block 1l which is slidable verticallyv on guideways 12 and secured to the lower end of a worm shaft 13 which extends upwardly` through an opening 14 in the frame 1. 4`The: driving system u. and structure thus far described is old and forms no part of the present invention.

A casting consisting of a bevel gear 15,v a cylindrical extension 16 and an enlarged cup-shaped portion 17 is rotatably mounted in the opening u 14. The casting is provided with a threaded portion 18 which engages somewhat loosely the threads on the worm shaft ylil so that the worm may move a short distance longitudinally, for example about gk, independently of the casting. A substantially flat plate 19 is loosely mounted at the lower end or opening in the cup-shaped member 17 and is provided with a plurality of projecting pins 20 which fit loosely in cooperating slotsy 21 in the cup-shaped member 1'?. These pins are provided with enlarged head portions 22. A coiled spring 23 surrounds the worm shaft 13 and bears against the bottom of the cup-shaped member 17 and the plate 19 thus urging the worm shaft and grinding wheel any one adjusted The tension of spr movingpins 20 and beadjustedby re.

plate l9onshaf ing 23 may turninsthe A relatively small4 bevel gear 24 engages the bevel gear 15 and may be operated by means of a hand wheel 25 to provide longitudinal adjustment of the grinding wheel. When the bevel gear 24 is rotated in either direction, the cupshaped member 1'1 and the plate 19 are also roe im desired.

With a grinding machine of the type described, it is possible to quickly grind very'hard metals of the character described in the above mentioned Schrter patent so that they will be absolutely flat. For example, if one ground tool bit is rubbed across the surface of a second ground tool bit so as to exclude any air lm from between them it will be found that the surfaces are so flat that very often the lower tool bit will stick to the upper tool bit when the latter is lifted. Moreover, with vmy improved grinder the edges of the tool bit are not chipped and the wear on the grinding'wheel is far less than is the case in ther ordinary grinding machine.

In Fig. 2, I have illustrated my invention in connection with a cutter grinder. In this figure a pedestal 26, usually employed with such grinders, is provided `at its upper end with an integral U-shaped bracket 27 .which carries bearings 28 and 29 for a shaft 30 driven by step pulleys 31y and 32. Shaft 30 is provided at the outer end thereof with a grinding wheel 33. The opposite end of the shafty is provided with an outward direction toward the work to be ground. The force applied -to shaft 30 by the spring 37 may be adjusted by manipulation of a screw plug 38 mounted in a cap 39 which is secured to the supporting member 29 for bearing 1,945,396-- l tated andthe worm shaftA 13 moved either up- Spring 37 normally urges the step pulleys 31 and 32 against a ball race 40 conned between plates 41 loosely mounted on shaft 30. Shaft 30. may move inwardly and away from the work a small distance which usually will lnot exceed gli", the amount of inward movement being limited by a nut 42 secured to the end of bearing 29, as clearly indicated in Fig. 2.

Although I have illustrated my invention in with surface and cutter grinders, it is clear that the invention is not limited to those machines only but may be applied to various types of grinding machines.

What I claim as new and desire to secure by Letters Patent of the United States, is:v

1. In a grinding machine, a grinding Wheel,

, yieldingly hold said wheel in contact with the work.

v2. In an automatic surface grinding machine, a grinding wheel, means for adjusting the position of the wheel, said means including a worm shaft, a member rloosely and rotatably mounted on said shaft but held against longitudinal moveing connected to lsaid. first member to rotate therewith but to move -n a longitudinal direction independent thereof, and resilient means interposed between said members to urge said grinding CARL I-I. GERLING. 

